Abstract
Processing poultry meat generates large amounts of protein-rich side streams. Enzymatic hydrolysis is widely used for upcycling but often produces bitter and unpalatable products. Membrane filtration may improve quality, but its effects on sensory properties and composition remain unclear. This study examined microfiltration (MF), nanofiltration (NF), and diafiltration of a poultry protein hydrolysate using sensory analysis, 1H NMR metabolomics, and volatile compounds. MF removed lipids and suspended particles, reducing flavour intensity and lipid oxidation products, with hexanal reduced by 94-96%. NF reduced ash and low-molecular-weight metabolites while increasing protein levels. Despite these changes, NF had limited additional sensory effects and slightly increased bitterness, likely related to reduced salt levels and increased peptide concentration. Altogether, these findings highlight the role of matrix effects in flavour perception and support strategies to improve the sensory quality of poultry protein hydrolysates.